{"product_id":"cmmg-5-7x28mm-8in-barrel-bolt-carrier-group-kit-radial-delayed-blowback-57d88c3","title":"CMMG 5.7x28mm 8in Barrel \u0026 Bolt Carrier Group Kit, Radial Delayed Blowback, 57D88C3","description":"\u003ch2\u003eProduct Description\u003c\/h2\u003e\n\u003cp\u003eThe CMMG 5.7x28mm Barrel and Bolt Carrier Group (BCG) Kit is built for assembling an AR-platform upper in 5.7x28mm using CMMG’s patented Radial Delayed Blowback operating system. Compared to typical direct blowback setups, Radial Delayed Blowback helps reduce bolt carrier group weight and delivers less felt recoil while maintaining reliable function. This kit is designed to assemble into a mil-spec AR-15\/Mk4 upper and is compatible with a CMMG Mk57 lower, or a standard Mk4\/AR-15 lower when paired with CMMG 5.7 AR conversion magazines.\u003c\/p\u003e\n\n\u003ch2\u003eProduct Highlights\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e8-inch 5.7x28mm barrel and matching 5.7x28mm bolt carrier group kit for AR-platform builds\u003c\/li\u003e\n  \u003cli\u003eCMMG Radial Delayed Blowback system for reduced felt recoil versus straight blowback designs\u003c\/li\u003e\n  \u003cli\u003eDesigned for mil-spec AR-15\/Mk4 upper receiver assembly\u003c\/li\u003e\n  \u003cli\u003eWorks with CMMG Mk57 lower or standard AR-15 lower (with CMMG 5.7 conversion magazines)\u003c\/li\u003e\n  \u003cli\u003eBlack finish to match common AR build aesthetics\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eSpecs\u003c\/h2\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e CMMG\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eProduct Type:\u003c\/strong\u003e Barrel \u0026amp; Bolt Carrier Group (BCG) Kit\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCaliber:\u003c\/strong\u003e 5.7x28mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBarrel Length:\u003c\/strong\u003e 8 in\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eColor\/Finish:\u003c\/strong\u003e Black\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompatible Platforms:\u003c\/strong\u003e Mil-spec AR-15 \/ Mk4 upper; CMMG Mk57 lower or AR-15 lower with 5.7 conversion magazines\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOperating System:\u003c\/strong\u003e Radial Delayed Blowback\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 810097502406\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 57D88C3\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cem\u003eDisclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product’s manufacturer.\u003c\/em\u003e\u003c\/p\u003e","brand":"CMMG","offers":[{"title":"Default Title","offer_id":44077165019258,"sku":"FLX-184853","price":450.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1679\/0365\/files\/283696213.png?v=1767642540","url":"https:\/\/tlooutdoors.com\/products\/cmmg-5-7x28mm-8in-barrel-bolt-carrier-group-kit-radial-delayed-blowback-57d88c3","provider":"TLO Outdoors","version":"1.0","type":"link"}